Could be my one guarantee of getting paid (5,5)
I believe the answer is:
money order
'getting paid' is the definition.
I can't judge whether this definition defines the answer.
'could be my one guarantee' is the wordplay.
'could be' is an anagram indicator.
'guarantee' becomes 'order' (I can't justify this - if you can you should give a lot more credence to this answer).
'my'+'one'='myone'
'myone' with letters rearranged gives 'money'.
'money'+'order'='MONEY-ORDER'
'of' is the link.
Can you help me to learn more?
(Other definitions for money order that I've seen before include "way to make payment?" , "Means to pay" .)